\tracingonline=2
\tracingcommands=2
\tracingmacros=2
\tracingrestores=2

%countdef
\countdef\x=10
\show\x

\x=40
\showthe\x
\showthe\count10
\count20=\x
\showthe\count20

\countdef\x=-1
\show\x
\countdef\x=256
\show\x

%dimendef
\dimendef\x=10
\show\x

\x=40pt
\showthe\x
\showthe\dimen10
\dimen20=\x
\showthe\dimen20

\dimendef\x=-1
\show\x
\dimendef\x=256
\show\x

%skipdef
\skipdef\x=10
\show\x

\x=40pt plus 4fill
\showthe\x
\showthe\skip10
\skip20=\x
\showthe\skip20

\skipdef\x=-1
\show\x
\skipdef\x=256
\show\x

%muskipdef
\muskipdef\x=10
\show\x

\x=40mu plus 4fill
\showthe\x
\showthe\muskip10
\muskip20=\x
\showthe\muskip20

\muskipdef\x=-1
\show\x
\muskipdef\x=256
\show\x

%toksdef
\catcode`{=1
\catcode`}=2

\toksdef\x=10
\show\x

\x={\a \b \c}
\showthe\x
\toks20=\x
\showthe\toks20

\toksdef\x=-1
\show\x
\toksdef\x=256
\show\x

%chains
\def\L{\show\x}
\def\M{\show\y}
\toksdef\L0\M{}
\show\L

\def\L{\show\x}
\toksdef\L0\L{}
\show\L

\end
